1. Field of the Invention
The present invention relates to an extracting method, an extracting apparatus, a separating method and a separating apparatus. The invention relates to a technique for selectively extracting an object contained in a liquid.
2. Description of the Related Art
In recent years, dioxin or the like generated from garbage incinerators and the like is recognized as serious environmental problem, and it is an important problem to measure and manage a discharge density of the dioxin. Currently, a method of measuring a density of the dioxin or the like is defined by Japanese Industrial Standards (JIS).
In the case where the dioxin or the like is measured, in order to extract the dioxin contained in water, similarly to a conventional solvent extracting method, water and an organic solvent are put into a separating funnel or the like and are shaken to be mixed, the dioxin in the water is incorporated into the organic solvent and only the organic solvent is extracted so as to be separated from the water.
However, this method requires a lot of solvent, long time and a lot of costs.
Recently, an attention is paid to xcexc-TAS (xcexc-Total Analysis System) which refines chemical analysis and synthesizing apparatuses and chemical analysis and synthesizing methods using a micromachine technique. The xcexc-TAS, which is refined more finely as compared with conventional apparatuses, has the merits such that an amount of samples is small, reacting time is short and an amount of refuse is small. In the case where the xcexc-TAS is adapted to the environment measuring field or the like, it has the merits that usage of reagent and organic solvent is small and reacting time (measuring time) is short, and further since an apparatus is small, the measurement can be made on the ground, so that the immediacy of an inspection is expected to be improved.
However, conventionally a technique for extracting a solvent using a micro fluid system to which the micromachine technique is applied has not been found.
For example, in a very narrow channel having a width of several dozen to several hundred xcexcm, the viscosity of a liquid is dominant, and it is difficult to stir and mix liquids. For this reason, in order to incorporate the dioxin contained in the water into the organic solvent, it is inefficient to stir water and organic solvent in a channel.
In addition, it is desirable that only an organic solvent is extracted from a small amount of mixed water and organic solvent in a microarea and to separate it from the water.
Therefore, a first technical problem to be solved by the invention is to provide an extracting method, an extracting apparatus and a chip for the extracting apparatus which incorporate a substance contained in a first liquid into a second liquid efficiently in a microarea.
In addition, a second technical problem to be solved by the present invention suggests a separating method, a separating apparatus and a chip for the separating apparatus which separate a second liquid from mixed first liquid and second liquid in a microarea.
In order to solve the first technical problem, the present invention provides an extracting method which is basically characterized in that a layered first liquid and a layered second liquid come in contact with each other, and a substance in a first laminar flow of the first liquid is moved into a second laminar flow of the second liquid. More concretely, the following extracting method is provided.
The extracting method is to incorporate the substance contained in the first liquid into the second liquid so as to extract the substance. This extracting method has the first step and the second step. In the first step, the first liquid and the second liquid are transferred into a channel so as to alternately come in contact with each other respectively in not less than one or two laminar state, and the substance in the first laminar flow of the first liquid is moved to the second laminar flow of the second liquid. In the second step, the second liquid is separated from the first liquid in a lower stream side of the channel.
In the first step, the first fluid and the second fluid are allowed to flow into the channel with a very small width so as to be in the laminar state. When two or more first laminar flows and the second laminar flows exist, the first laminar flows and the second laminar flows are arranged alternately so as to come in contact with each other.
Generally the substance in the liquid diffuses voluntarily. Namely, molecules of a medium (liquid) continually collide with small matters (particles of the substance) in the medium, and the small matters move irregularly in the medium. Due to this Brownian movement, the small matters diffuse in the medium. A relative interfacial area of the liquid becomes large in the microarea (namely, a surface area becomes wider as compared with a volume), and the diffusion speed becomes abruptly high. For this reason, the particles of the substance in the first laminar flow move to the second laminar flow quickly. Namely, the particles are incorporated into the second liquid. In this case, it is preferable that the particles of the substance return with difficulty from the second laminar flow to the first laminar flow, and for example, it is preferable that the substance is easily incorporated into the second liquid easier than into the first liquid. When the substance is dioxin or the like, the first fluid can be water and the second fluid can be an organic solvent. Moreover, in order to diffuse it efficiently, it is preferable that a flow velocity of the first laminar flow is equal with a flow velocity of the second laminar flow and the flow velocities do not relatively differ.
According to the above method, the flow of the laminar flow and the particle diffusion phenomenon in the channel are used, so that the substance contained in the first liquid can be incorporated into the second liquid efficiently in the microarea.
In the first step, even if the liquids are sequentially transferred, the liquids may be stopped in the middle of the channel.
In the second step, only the second liquid is collected, so that the substance contained in the first liquid can be extracted.
Preferably at the first step, a width of one laminar flow is not more than 50 xcexcm. When the width is not more than 50 xcexcm, a Reynolds number becomes small, and the liquid is easily transferred in the channel in the laminar state.
The second step can collect only the second liquid in the following various forms.
Preferably, the second step includes a channel branching step. In the channel branching step, in the lower stream side of the channel, the first laminar flow is allowed to flow into a first branch channel, and the second laminar flow is allowed to flow in a second branch channel. In this case, the channels is branched for each liquid in the laminar state, so that the second liquid can be separated from the first liquid easily.
Preferably, the second step includes a charging step. In the charging step, a vicinity of an inlet of the first branch channel or the second branch channel is charged. Polarity is provided to the first liquid or the second liquid and the other liquid has no polarity by the charging step, one liquid having a polarity is activated so as to enter the charged first branch channel or second branch channel, and thus the liquids can be separated more efficiently. For example, nonpolar molecules such as petroleum ether, carbon tetrachloride, benzene, xylene, nitrobenzene and iodine can be separated from water having polarity. As for a mixed liquid composed of three or more liquids, in the case where only one liquid has polarity or where only one liquid is nonpolar, the one liquid can be separated from the other liquids.
In addition, the present invention provides the following separating method in order to solve the second technical problem.
The separating method separates a second liquid from mixed first liquid and second liquid. The separating method has the first step and the second step. In the first step, the mixed first liquid and second liquid are allowed to flow into the channel. The channel is composed of a first space and a second space. The first space is provided with a microstructure, and one of the first liquid and the second liquid flows relatively easily. The second space extends along the first space and is connected with the first space. In the second step, the second liquid is collected in a lower stream side of the first space or the second space in which the second liquid flows.
According to the above method, when the mixed first and second liquids are allowed to flow in the channel, one of the first and second liquids which flow relatively easily into the first space flows in the first space, and the other liquid flows in the second space. For example, the structures undergo a hydrophilic treatment and are provided with a suitable functional group, so that one of the first and second liquids can easily flow relatively in the first space. Since the first liquid and the second liquid separate from each other and the second liquid flows in the first space or the second space, the second liquid can be collected in the lower stream.
Therefore, the second liquid can be separated from the mixed first and second liquids in the microarea.
In the above method, the microstructure is constituted suitably, so that one of the first and second liquids can be allowed to flow relatively easily in the first space of the separated channel. For example, the microstructure contains a lot of elements, and a distance (gap) between the adjacent elements is not more than 10 xcexcm. The microstructure may be made of a porous substance in which microholes are opened on all sides, or a fiber block.
Preferably, the structure is a column-shaped structure which extends from the first space side to the second space side.
A fluid which flows with relative difficulty in the first space of the first liquid and the second liquid can move easily along the extending direction of the microstructure towards the second space. Therefore, a separating efficiency of the liquid can be heightened.
More preferably, one of the first liquid and second liquid contains water. The above structure undergoes a water-repellent treatment. In this case, the first or second liquid containing water repels the microstructure which underwent the water-repellent treatment so as to move to the second space, so that the liquid separating efficiency can be heightened. In the case where only one liquid of a mixed liquid composed of three or more liquids has water and affinity, the one liquid can be separated from the other liquids.
Further, in order to solve the above first technical problem, the present invention provides an extracting apparatus which is basically characterized in that a first liquid space in which a first liquid is to flow in a layered state and a second liquid space in which a second liquid is to flow in a layered state are arranged so as to come in contact with each other in the layer direction. More concretely, the extracting apparatus is constituted in the following manner.
The extracting apparatus incorporates a substance contained in the first liquid into the second liquid and extract the substance. The extracting apparatus has a channel and a separating section. The first liquid and the second liquid flow in the channel with them contacting alternately in not less than one or two laminar state, and the substance in the first laminar flow of the first liquid moves to the second laminar flow of the second liquid. The separating section is connected to a lower stream side of the channel and separates the second liquid from the first liquid.
According to the above constitution, the first fluid and the second fluid are allowed to flow in a very small width of the channel so as to be capable of being in a laminar state. In the case of two or more first and second laminar flows, the first laminar flows and the second laminar flows are arranged alternately so as to come in contact with each other.
Generally, the substance in the liquid diffuses voluntarily. Namely, molecules of a medium (liquid) continually collide with small matters (particles of the substance), and the small matters move in the medium irregularly. Due to this Brownian movement, the small matters diffuse in the medium. In the microarea, the relative interfacial area of the liquid becomes large (namely, a surface area becomes larger as compared with a volume), and the diffusion speed becomes abruptly high. For this reason, the particles of the substance in the first laminar flow move to the second laminar flow quickly. Namely, the particles are incorporated into the second liquid. In this case, it is preferable that the particles of the substance return with difficulty from the second laminar flow to the first laminar flow, and for example, it is preferable that the substance is incorporated into the second liquid more easily than into the first liquid. When the substance is dioxin or the like, the first fluid can be water and the second fluid can be an organic solvent. Moreover, in order to diffuse the substance efficiently, it is preferable that the flow velocity of the first laminar flow is equal with the flow velocity of the second laminar flow and the flow velocities do not vary relatively.
According to the above constitution, the flow of the laminar flow and the diffusion phenomenon of the particles in the channel are used, so that the substance contained in the first liquid can be incorporated into the second liquid efficiently in the microarea.
In the separating section, only the second liquid is collected, so that the substance contained in the first liquid can be extracted.
Preferably, in the channel, a width of one laminar flow is not more than 50 xcexcm. When the width is not more than 50 xcexcm, a Reynolds number becomes small, and the liquid can be easily transferred in the laminar state in the channel.
The separating section can collect only the second liquid in the following various forms.
Preferably the separating section includes a first branch channel in which the first laminar flow flows, and a second branch channel in which the second laminar flow flows. In this case, the channel is branched for each liquid in the laminar state, so that the second liquid can be separated from the first liquid easily. More preferably, a charging section, which charges a vicinity of an inlet of the first branch channel or the second branch channel is provided.
According to the above constitution, in the case where the first liquid or the second liquid has polarity and the other one is nonpolar, one liquid having polarity is activated so as to enter the charged first branch channel or second branch channel, so that the liquid can be separated more efficiently. For example, nonpolar molecules such as petroleum ether, carbon tetrachloride, benzene, xylene, nitrobenzene and iodine can be separated from water having polarity. As for a mixed liquid composed of three or more liquids, in the case where only one liquid has polarity or where only one liquid is nonpolar, the one liquid can be separated from the other liquids.
Further, in order to solve the above second technical problem, the present invention provides a separating apparatus having the following constitution.
The separating apparatus separates the second liquid from the mixed first liquid and second liquid. The separating apparatus has a first space, a second space and a discharge port. The first space is provided with a microstructure, and one of the first liquid and the second liquid flows relatively easily. The second space extends along the first space and is connected to the first space. The discharge port is connected to a lower stream side of the first space or the second space where the second liquid flows, and the second liquid flows therein.
According to the above constitution, when the mixed first and second liquids are allowed to flow in the first space and the second space, one of the first liquid and the second liquid which flows relatively easily in the first space flows in the first space, and the other liquid flows in the second space, so that the first liquid and the second liquid are separated from each other. For example, the structures undergo a hydrophilic treatment or a suitable functional group is provided, so that one of the first liquid and the second liquid can be allowed to flow in the first space relatively easily. Since the second liquid flows in one of the first space or the second space, the second liquid can be collected from the discharge port. Therefore, the second liquid can be separated from the mixed first liquid and the second liquid in the microarea.
In the above constitution, the microstructure is suitably constituted, so that one of the first liquid and the second liquid can be allowed to flow in the first space of the separated channel relatively easily. For example, the microstructure includes a lot of elements, and a distance (gap) between the adjacent elements is not more than 10 xcexcm. The microstructure may be composed of a porous substance in which microholes are opened on all sides, or a fiber block.
Preferably, the structure is a column-shaped structure which extends from the first space side to the second space side.
A fluid which flows with relative difficulty in the first space of the first liquid and the second liquid can move easily along the extending direction of the microstructure towards the second space. Therefore, a separating efficiency of the liquid can be heightened.
More preferably, one of the first liquid and second liquid contains water. The above structure undergoes a water-repellent treatment.
According to the above constitution, the first or second liquid containing water repels the microstructure which has undergone the water-repellent treatment so as to move to the second space, so that the liquid separating efficiency can be heightened. In the case where only one liquid of a mixed liquid composed of three or more liquids has water and affinity, the one liquid can be separated from the other liquids.
Further, in order to solve the above first technical problem, the present invention provides a chip for the extracting apparatus having the following constitution.
The chip to be used for the extracting apparatus is used for the extracting apparatus which incorporates the substance contained in the first liquid into the second liquid so as to extracts the substance. The chip has a channel. The first liquid and the second liquid are transferred in the channel so as to come in contact with each other alternately in not less than one or two laminar state, and the substance in the first laminar flow of the first liquid can be moved into the second laminar flow of the second liquid.
In the above constitution, the first fluid and the second fluid are allowed to flow in a very small width of the channel so as to be capable of being in the laminar state. In the case of two or more first laminar flows and second laminar flows, the first laminar flows and the second laminar flows are arranged alternately so as to be capable of being in contact with each other.
Generally, the substance in the liquid diffuses voluntarily. Namely, molecules of a medium (liquid) continually collide with small matters (particles of the substance) in the medium, and the small matters move in the medium irregularly. Due to this Brownian movement, the small matters diffuse in the medium. In the microarea, the relative interfacial area of the liquid becomes large (namely, a surface area becomes larger as compared with a volume), and the diffusion speed becomes abruptly high. For this reason, the particles of the substance in the first laminar flow move to the second laminar flow quickly. Namely, the particles are incorporated into the second liquid. In this case, it is preferable that the particles of the substance return with difficulty from the second laminar flow to the first laminar flow, and for example, it is preferable that the substance is incorporated into the second liquid more easily than into the first liquid. When the substance is dioxin or the like, the first fluid can be water and the second fluid can be an organic solvent. Moreover, in order to diffuse the substance efficiently, it is preferable that the flow velocity of the first laminar flow is equal with the flow velocity of the second laminar flow and the flow velocities do not vary relatively.
According to the above constitution, the flow of the laminar flows and the diffusion phenomenon of the particles in the channel are used, so that the substance contained in the first liquid can be incorporated into the second liquid efficiently in the microarea.
Only the second liquid is collected, so that the substance contained in the first liquid can be extracted.
Preferably, in the channel, a width of one laminar flow is not more than 50 xcexcm. When the width is not more than 50 xcexcm, a Reynolds number becomes small, and the liquid can be easily transferred in the laminar state in the channel.
Preferably, a first branch channel and a second branch channel are provided. The first branch channel is connected to a lower stream side of the channel, and the first laminar flow flows therein. The second branch channel is connected to a lower stream side of the channel, and the second laminar flow flows therein. According to the above constitution, the channel is branched for each liquid in the laminar state, so that the second liquid can be separated from the first liquid easily. More preferably, a charging section, which charges a vicinity of an inlet of the first branch channel or the second branch channel is provided.
According to the above constitution, in the case where the first liquid or the second liquid has polarity and the other one is nonpolar, one liquid having polarity is activated so as to enter the charged first branch channel or second branch channel, so that the liquid can be separated more efficiently. For example, nonpolar particles such as petroleum ether, carbon tetrachloride, benzene, xylene, nitrobenzene and iodine can be separated from water having polarity. As for a mixed liquid composed of three or more liquids, in the case where only one liquid has polarity or where only one liquid is nonpolar, the one liquid can be separated from the other liquids.
Further, in order to solve the second technical problem, the present invention provides a chip for the separating apparatus having the following constitution.
The chip for the separating apparatus is used for the separating apparatus which separates a second liquid from mixed first liquid and second liquid. The chip has a first space, a second space and a discharge port. The first space is provided with a microstructure, and one of the first liquid and the second liquid flows relatively easily. The second space extends along the first space and is connected to the first space. The discharge port is connected to a lower stream side of the first space or the second space where the second liquid flows, and the second liquid flows therein.
According to the above constitution, when the mixed first and second liquids are allowed to flow in the channel, one of the first liquid and the second liquid which flows relatively easily in the first space flows in the first space, and the other liquid flows in the second space. For example, the structure undergoes a hydrophilic treatment or a suitable functional group is provided, so that one of the first liquid and the second liquid can be allowed to flow in the first space relatively easily. Since the first liquid and the second liquid are separated from each other and the second liquid flows in one of the first space and the second space, the second liquid can be collected on the lower stream side.
Therefore, the second liquid can be separated from the mixed first liquid and the second liquid in the microarea.
The microstructure is suitably constituted, so that one of the first liquid and the second liquid can be allowed to flow in the first space relatively easily. For example, the microstructure includes a lot of elements, and a distance (gap) between the adjacent elements is not more than 10 xcexcm. The microstructure may be composed of a porous substance in which microholes are opened on all sides, or a fiber block.
Preferably, the structure is a column-shaped structure which extends from the first space side to the second space side.
According to the above constitution, a fluid which flows with relative difficulty in the first space of the first liquid and the second liquid can move easily along the extending direction of the microstructure towards the second space. Therefore, a separating efficiency of the liquids can be heightened.
More preferably, one of the first liquid and second liquid contains water. The above structure undergoes a water-repellent treatment.
According to the above constitution, the first or second liquid containing water repels the microstructure which has undergone the water-repellent treatment so as to move to the second space, so that the liquid separating efficiency can be heightened. In the case where only one liquid of a mixed liquid composed of three or more liquids has water and affinity, the one liquid can be separated from the other liquids.